Subject: Avoid @Command([RefreshHideFormulas]) after opening a new form?
This is even less critical on the web, since all computations have been completed, before the site is rendered to HTML.
However, in the first place you really shouldn’t have the problem. Looks to me, like the form is corrupt. Try to create a new one and copy over the elements line by line.
Btw., I don’t remember from your original posting, if your Hide field was a number field, but it should be, of course.